Honoring the Theotokos
"'Mother of God', Theotokos, is the title that was officially attributed to Mary in the fifth century, to be exact, at the Council of Ephesus in 431, but which had already taken root in the devotion of the Christian people since the third century, in the context of the heated discussions on the Person of Christ in that period. This title highlights the fact that Christ is God and truly was born of Mary as a man: in this way his unity as true God and true man is preserved."
-Pope Benedict XVI, Homily in Ephesus on November 29, 2006.